ES3022635T3 - Composite system and method for reinforcing, in particular, structures made from reinforced concrete or masonry comprising a curable or cured matrix and textile reinforcement grid constituting said system - Google Patents

Abstract

Composite system for consolidating works, method for consolidating reinforced concrete or masonry works, and use of a composite structure. The invention relates to a composite consolidation system specifically for reinforced concrete or masonry works, comprising a hardenable or toughened matrix and a textile reinforcing grid, as well as these two elements considered individually. The objective of the invention is that this system allows the production of a hardened composite structure with improved mechanical properties, both in the short and long term (e.g., fall resistance, hardness, flexural/compression strength, durability, cohesion). This objective is achieved by the aforementioned system, in which the grid includes at least one layer formed: on the one hand, by a framework consisting of flat warp filaments and weft filaments; and, on the other hand, by a framework tying net; characterized in that the tying net is such as to ensure the geometric regularity and dimensional stability of the framework meshes before the grid is placed on the work to be consolidated. The invention also relates to a consolidation method, especially for works in reinforced concrete or masonry, the composite structure obtained as a result of this method, the dry and wet formulas of the hardenable matrix, and the consolidated works, especially in reinforced concrete or masonry.

Description

DESCRIPTION

Composite system and consolidation procedure, specifically, of reinforced concrete or masonry works comprising a hardenable or hardened matrix and textile reinforcement grid that constitutes this system

Technical field

The technical field of the invention is the consolidation, specifically, of reinforced concrete or masonry works, such as buildings, civil engineering constructions (bridges, tunnels, pipelines, etc.).

In particular, the invention relates to a composite system for consolidating, in particular, reinforced concrete or masonry works, comprising a hardenable or hardened matrix and a textile reinforcing grid, as well as these two elements together.

The invention also relates to a consolidation method, specifically, of reinforced concrete or masonry works, as well as to the composite structure obtained as a result of this method.

Dry and wet formulations of the hardenable matrix, which is preferably a hydraulic matrix, are also encompassed by the invention.

Consolidated structures, specifically reinforced concrete or masonry, are also an integral part of the invention.

Technological background

Reinforced concrete or masonry buildings are buildings that can be constructed with aggregate, reinforced concrete, or other materials, brick, rock, cement, plaster, lath, stony rubble, rubble, mortar, rubble, stone, rammed earth, plaster, or concrete bricks. These buildings are subject to alterations caused by the stresses they are subjected to and/or by climatic or environmental influences of any kind, including seismic events and/or, possibly, design and/or construction defects.

On the other hand, the function of a building can change. A home, for example, may be converted into a space for a tertiary industrial activity. Such a change may be accompanied by a change in the stresses the building experiences. This could imply, for example, an upward trend in the load a floor can support.

All these causes require reinforcing the structure of the affected buildings.

Some well-known reinforcement methods involve adhering carbon fiber woven fabrics or flakes to structural elements (floors, beams, walls, posts, tunnels, pipelines). These woven fabrics or flakes are impregnated with a hardenable resin (epoxy resin) and attached to these structural elements. After the resin rapidly hardens, the result is a carbon/resin woven or flaked composite material that increases the mechanical strength as well as the ductility of the consolidated structure.

These known procedures present two major drawbacks:

-epoxy resins should only be applied on dry substrates (there is no adhesion on wet concrete);

-From a health perspective, they are potentially toxic, polluting and are likely to emit dangerous fumes in the event of a fire.

Also known from patent application DE19525508A1 is a method for improving the durability of parts of a building made of concrete or masonry, by means of a multi-layer coating obtained by applying, to at least one surface of said parts of the building, a mineral matrix formed by a layer of hydraulic mortar [cement (1): ashes (0.33): water (0.36): styrene/acrylate dispersion (0.12)], which is reinforced with a lattice or a porous textile based on glass, carbon or aramid fibers", and which has a modulus of elasticity greater than 20,000 N/mm2, an elongation at break greater than 0.4 % and surface densities of more than 75 g/m2. The lattice or porous textile is included in the mortar which has not yet hardened. These operations of forming a layer of hydraulic mortar and of including a lattice or a porous textile are repeated at least once. At all times, the lattice or porous textile is well embedded in the mortar layer that has not yet hardened, to form a hardened composite material in which the hardened mortar forms a matrix well intermixed with the lattice or porous textile.

European patent EP0994223B1 discloses a heat-treated fabric useful as a framework for construction work, wherein the warp is made up of yarns whose fibers (12K 800 tex carbon yarns) have high moduli, a coefficient of elasticity under tension greater than 10 GPa and a tensile yield strength greater than 600 MPa, and wherein the weft is made up of glass yarns (60 tex) coated with a thermoadhesive polymeric material (40 tex/hot-melt polyamide) with a melting temperature between 40 and 250 °C. The amount of thermoadhesive polymeric material is between 10 and 300% by weight with respect to the glass yarns. This fabric is applied to building structures by means of an impregnating resin. To do this, the surface of the building structure in question is coated with a layer of impregnating resin, reinforcing fabric is included in this first layer, a second layer of impregnating resin is applied, reinforcing fabric is again included in this second layer on which a third layer of impregnating resin is placed.

European patent EP1245547B1 describes a cementitious mortar intended for use in reinforcing construction elements, in combination with synthetic fiber lattices (carbon fiber, aramid, glass, polyester, polyethylene or others) with a mesh size between 10 and 35 mm. The mortar contains cement, a fluidifying copolymer resin, a thixotropic additive derived from cellulose, such as methylhydroxyethylcellulose or methylcellulose, a fine filler, for example, based on quartz (500 micrometers), fly ash or a marble powder and optionally silica, as well as other additives.

European patent EP1893793B1 proposes an improvement to the reinforcing lattices used in the means for consolidating construction elements, disclosed in document EP1245547B1. This improvement consists in the fibers constituting said reinforcing lattices being poly[benz (1, 2-D: 5,4-D') bisoxazol-2,6-diyl-1, 4-phenylene] fibers. Document KR101308513B1 discloses a grid according to the preamble of claim 1.

Technical problem - Objectives of the invention

All these prior art technical proposals are marginal adjustments that do not allow for significant improvements, specifically in the mechanical properties of composite reinforcement structures (cement matrix/carbon and/or glass fabric) in buildings or civil engineering works.

In this context, the technical problem underlying the present invention is to satisfy at least one of the objectives set out below:

(i) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, enabling the production of a toughened composite structure with improved short-term and long-term mechanical properties (e.g., weakening behaviour, hardness, flexural/compressive strength, durability, cohesion).

(ii) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a hardened composite structure, mechanically strong and sufficiently ductile to perform its function of consolidating reinforced concrete or masonry works in the best possible way.

(iii) Provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a hardened composite structure that is mechanically effective and adheres perfectly to the support to be consolidated, specifically in humid implementation conditions.

(iv) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a mechanically efficient, toughened composite structure and for which the textile reinforcing grid can be easily manufactured on an industrial scale.

(v) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a hardened composite structure that is mechanically effective and easy to implement by an operator during consolidation.

(vi) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a hardened, mechanically effective composite structure and which does not require special storage conditions for either the reinforcing grid or the matrix.

(vii) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, enabling the production of a toughened, mechanically effective and economical composite structure.

(viii) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which will produce a toughened, mechanically effective and durable composite structure.

(ix) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a hardened, mechanically effective composite structure, whatever the morphology of the work to be consolidated, in particular in the case of pipelines, particularly sewer network pipelines.

(x) Provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or hardened matrix and a textile reinforcing grid, which allows easy covering of pipes to consolidate them, particularly pipes in sewer networks.

(xi) Provide a composite system for consolidating masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, which allows the production of a toughened, mechanically efficient and eco-compatible composite structure, i.e. which avoids as far as possible the use of compounds that may be harmful to operators and/or the environment.

(xii) To provide a composite system for consolidating reinforced concrete or masonry works comprising a hardenable or toughened matrix and a textile reinforcing grid, allowing the production of a mechanically effective, hardened composite structure, wherein the hardenable matrix is a dry composition (e.g. cementitious) which gives rise, after mixing with a liquid (e.g. water), to a wet, easily sprayable formulation, simple to implement, having a paste-like consistency and viscosity allowing pumping by a spraying machine and a sufficiently long workability to perform the mixing and the realization of the consolidation structure, while remaining economical and stable after mixing.

(xiii) Provide a composite structure obtained from the system mentioned in objectives (i) to (xii) above, and which is mechanically effective, easy to realize in various contexts and cost-effective.

(xiv) Provide a composite structure obtained from the system mentioned in objectives (i) to (xii) above, and which can be used to increase the resistance to seismic loads of reinforced concrete or masonry works.

(xv) Provide a procedure for consolidating reinforced concrete or masonry works, using the system mentioned in objectives (i) to (xii) above, which is easy to implement in various contexts, while remaining economical.

Brief description of the invention

It is to the inventors' credit that one of the key points for this type of composite matrix/textile reinforcement structures lies in optimizing the anchoring of the matrix in the textile frame. In particular, the inventors have discovered the importance of good interpenetration and uniform interpenetration of the cementitious matrix through the gaps in the reinforcing fabric. Homogeneous entrapment of the reinforcing fabric by the cementitious matrix is, in fact, a way to avoid mechanical shearing phenomena, which can negate the desired consolidation.

Taking these findings into account, the inventors propose a solution to the problem posed in all or part of the objectives listed above. This solution lies, at least in part, in the implementation of a textile reinforcement comprising a means of geometric and dimensional stabilization of the mesh.

It follows that the present invention relates to, in a first of its aspects, a composite system according to claim 2 for consolidating works, specifically reinforced concrete or masonry, comprising a hardenable or hardened matrix and a textile reinforcement grid, wherein the grid comprises at least one layer formed:

- on the one hand, by a frame consisting of flat warp threads and weft threads;

- and, on the other hand, by a frame fastening net;

where the tying network is such that it guarantees the dimensional stability under tension of the frame meshes, before the application of the grid on the work to be consolidated,

where the tying net of the frame is a weave consisting of warp elements and weft elements, and where this weave is a gauze weave; each warp element of this weave comprising at least two tying threads, preferably two, and each weft element of this weave comprising at least one tying thread, preferably one, and

where:

• each warp element of the weave comprises two warp tying threads and each weft element of the weave comprises one weft tying thread,

• one of the two binding threads passes through the same side C1 of all the weft threads of the frame,

• the other warp tie thread passes through the same side C2 opposite to C1 of all the weft threads of the frame,

Between two successive weft threads of the frame, the warp tie threads cross before the weft weave thread, pass on either side of the weft tie thread, and then cross again to grasp the weft thread of the frame.

This particular tying network according to the invention ultimately makes it possible to obtain a composite structure for consolidating works, specifically reinforced concrete or masonry, which has the expected mechanical properties in terms of strength and ductility, in terms of adherence to the support to be consolidated and in terms of ease of implementation and storage.

According to other aspects of the invention, the invention relates to the following elements taken as such and independently of each other: the textile reinforcement grid according to claim 1 and the hardened composite structure comprising a matrix/grid placed in the work to be consolidated.

In particular, the invention relates to a composite structure having an elastic tensile modulus MTE of less than or equal to, in MPa and in an increasing order preferably, 100,000, 80,000, 70,000.

According to another of its aspects, but which is not claimed, the invention focuses on the use of a composite structure having an elastic tensile modulus MTE of less than or equal to, in MPa and in an ascending order preferably, 100,000, 80,000, 70,000, to increase the resistance to seismic loads of a reinforced concrete or masonry work, said structure being obtained from a composite system for consolidating works, comprising a hardenable or hardened matrix and a textile reinforcement grid, wherein the grid comprises at least one layer formed by a framework constituted by flat warp threads and weft threads and has dimensional stability under tension of the meshes of the framework, before the application of the grid on the work to be consolidated.

According to another of its aspects, the invention also relates to a consolidation method according to claim 8 of a work, which consists of gluing the grid according to the invention onto the work with the matrix according to the invention, after having mixed said matrix with a liquid, preferably water, to obtain a hardenable wet matrix.

According to another aspect, not claimed, the invention relates to a wet formulation comprising the matrix according to the invention mixed with a liquid, preferably water, as well as the method for preparing this wet formulation.

According to another of its aspects, the invention aims to use, according to claim 10, a grid according to the invention to consolidate a work, specifically of reinforced concrete or masonry, by gluing using a wet formulation according to the invention.

Definitions

Throughout this presentation, any singular means either a singular or a plural.

The definitions given below as examples may be used for the interpretation of this exposition:

•"mortar" means a dry or moist or hardened mixture of one or more organic and/or mineral binders, granules with a diameter < 5 mm (sand-aggregates) and possibly fillers and/or additives and/or adjuvants.

• "substantially" means more or less close to 10%, or even more or less close to 5%, with respect to the unit of measurement used.

• The term "d50" used in this presentation to refer to the particle size criterion designates the mean diameter. This means that 50% of the particles have a size less than "d50." Particle size is measured by sieving according to standard EN12192-1.

Detailed description of the invention

RACK

The grid according to the invention has at least one essential characteristic to obtain an optimal reinforcement of the material to which the system is applied:

-The dimensional stability of the grid under tension.

This feature is preferably associated with the following additional feature:

-The geometric regularity of the grid ensures that the stresses are distributed evenly across the entire surface affected by the reinforcement;

Dimensional stability under tension and, advantageously, geometric regularity, directly influence the grid's ability to homogeneously recover stresses across the entire surface affected by the reinforcement.

Dimensional stability under tension is rated as follows in a TS test defined below:

The deformation of a 40 x 40 cm sample suspended by its two upper corners in a vertical plane and subjected to the tensile stress of a mass of 1 (D1 strain) or 2 kg (D2 strain) fixed to the center of the lower edge of the sample, is such that:

• D1 less than or equal to, in cm and in ascending order preferably: 2.5; 1.5; 1.0; 0.8; 0.6; 0.5; 0.3; 0.2; 0.1; • D2 less than or equal to, in cm and in ascending order preferably: 5; 4; 3; 2; 1.8; 1.6; 1.5; 1.4; 1.2; 1.0;

Geometric regularity can also be assessed by a TR test defined below:

The standard deviation in % with respect to the mean of the surfaces of a random panel of 20 reinforcing slits (in the attached figures, the frame is designated by reference 2 and the slits or meshes of this frame are designated by reference 4, Fig. 1 and 7) or a panel of 20 slits of the tying net (in the attached figures, the tying net is designated by reference 3 and the slits or meshes of this tying net are designated by reference 5, Fig. 7), of a 40 x 40 cm grid sample is less than or equal to 15%, preferably to 10%, and even more preferably to 8%.

This dimensional stability of the grating under tension, and, advantageously, the geometric regularity of this grating, in particular, immediately after its manufacture, or even after being packaged in rolls immediately after its manufacture, guarantee its ability to not deform and are ensured, in particular, by the frame's tying net.

According to a notable embodiment of the invention, dimensional stability under tension, or even geometric regularity, is promoted by coating the grid, which allows the assembly to be "solidified" during the grid manufacturing process and guarantees almost perfect dimensional stability of the grid during the stresses that may occur during the handling steps prior to its implementation, as well as when the reinforcement is placed.

Thus, according to a preferred feature of the invention, at least part of the wires of the grid are coated/impregnated with at least one polymer, preferably chosen from the group comprising, or better still constituted by:

• (meth)acrylic (co)polymers, advantageously selected from the subgroup comprising, or better still consisting of, copolymers of alkyl esters advantageously comprising from 1 to 8 carbon atoms, with acrylic acid or methacrylic acid, in particular those chosen from the family comprising, or better still consisting of, preferably methyl acrylate, ethyl acrylate, butyl acrylate, ethyl-2-hexyl acrylate and their corresponding ones with methacrylic acid; and mixtures thereof;

• (co)polymers of vinyl esters advantageously selected from the subgroup comprising, or better still consisting of, homopolymers and copolymers of vinyl acetate, in particular those chosen from the family comprising, or better still consisting of, copolymers of vinyl acetate and ethylene, (co)polymers of vinyl chloride such as copolymers of vinyl chloride and ethylene, (co)polymers of vinyl laurate, (co)polymers of vinyl versatate, (co)polymers of vinyl esters of alpha monocarboxylic acids, saturated or not, branched or not, advantageously comprising 9 or 10 carbon atoms, homopolymers of vinyl esters of alkylcarboxylic acids, saturated or not, branched or not, advantageously comprising 3 to 8 carbon atoms, copolymers of these latter homopolymers with ethylene, vinyl chloride and/or other vinyl esters; and mixtures thereof;

• (co)polymers of styrene with butadiene or with one or more acrylic esters advantageously selected from the subgroup comprising, or better still consisting of, ethylenically unsaturated alkyl esters advantageously comprising from 1 to 8 carbon atoms of (meth)acrylic acid, preferably methyl acrylate, ethyl acrylate, butyl acrylate, ethyl-2-hexyl acrylate and their corresponding ones with methacrylic acid, and mixtures thereof;

• (co)hot-melt polymers, advantageously selected from the subgroup comprising, or better still consisting of, polyethylenes, polypropylenes, polyesters, polyamides, ethylene-propylene-diene monomer copolymers (EPDM) and mixtures thereof;

• and their mixtures.

Advantageously, the number of crossings of the tying threads in each slit of the non-woven frame is less than or equal to 4, preferably less than or equal to 2 and even more preferably equal to 1. The slits of the frame are not too hidden by the tying net.

According to a notable feature of the invention, the grid comprises carbon in an amount (in g/m2) comprised in the following intervals, in an ascending order preferably: [150-500]; [170-300]; [180-280]; [190-260]; [200-250].

The invention also relates to the consolidation grid according to claim 1, taken as such, independently of the system according to the invention. This consolidation grid for reinforced concrete or masonry structures comprises at least one layer formed:

- on the one hand, by a frame consisting of flat warp threads and weft threads;

- and, on the other hand, by a frame fastening net;

where the tying network is such that it guarantees the geometric regularity and dimensional stability under tension of the frame meshes, before the application of the grid on the work to be consolidated,

where the tying net of the frame is a weave consisting of warp elements and weft elements, and where this weave is a gauze weave; each warp element of this weave comprising at least two tying threads, preferably two, and each weft element of this weave comprising at least one tying thread, preferably one, and

where:

• each warp element of the weave comprises two warp tying threads and each weft element of the weave comprises one weft tying thread,

• one of the two binding threads passes through the same side C1 of all the weft threads of the frame,

• the other warp tie thread passes through the same side C2 opposite to C1 of all the weft threads of the frame,

Between two successive weft threads of the frame, the warp tie threads cross before the weft weave thread, pass on either side of the weft tie thread, and then cross again to grasp the weft thread of the frame.

Advantageously, this grid as defined in the present description, examples and figures, is preferably presented in the form of rolls or in the form of plates.

FRAME

The frame is woven or non-woven, preferably non-woven.

Advantageously, the weft threads and the warp threads of the frame are included in two parallel planes.

In practice, the weft threads of the frame are preferably arranged over the warp threads of this frame, whose warp threads form the face of the frame intended to come into contact with the work to be consolidated.

The superposition of the weft threads over the warp threads allows for a flat and straight surface.

According to a notable embodiment of the invention, the weft threads and the warp threads of the frame are each constituted by a bundle of filaments and have at least one of the following characteristics:

i. The filaments of a bundle are based on one or more materials chosen from the group comprising, or better still consisting of, carbon, glass, basalt, metals, plant materials, advantageously selected from the subgroup comprising, or better still consisting of, hemp, synthetic materials, advantageously selected from the subgroup comprising, or better still consisting of, aramid, poly[benz(1,2-D:5,4-D')bisoxazol-2,6-diyl-1,4-phenylene], polyethylene, polypropylene, polyamides, polyimides, polyesters;

carbon being preferable;

ii. The tensile strength (in MPa) of each thread is within the following ranges, preferably in ascending order: [1000-10000]; [2000-8000]; [3000-7000];

iii. The tensile modulus (in GPa) of each yarn is comprised within the following ranges, in preferably increasing order: [150-700]; [200-400];

iv. The elongation (in %) of each thread is within the following ranges, preferably in ascending order: [0.1-6]; [0.5-3.5]; [1-2.5].

Depending on this characteristic (i), the filaments in a bundle may be made from the same material or may be made from different materials, with each filament being made from a single material (e.g., metal filaments/filaments made from plant material, e.g., hemp), or they may even be made from a single material and/or different materials, with each filament being made from several materials. All combinations can be considered for a single bundle, or for all or part of it.

In a preferred embodiment of the invention, the warp threads and the weft threads of the frame each consist of a bundle of filaments or fibers, preferably carbon, grouped together.

These filaments or fibers, preferably carbon, are not mechanically connected to each other, so their width and thickness can vary depending on the tension of the threads.

As an example of a commercial reference of carbon threads that can be used to form the warp and weft threads of this mat, these include the threads marketed under the TORAYCA® brand by the company Soficar, with the references FT300/T300, T300J, T400 H, T600S, T700S, T700G, T800H, T800S, T1000G, M35J, M40J, M46J, M50J, M55J, M60J, M30S, M40.

TYING NET

The strands of the frame, preferably carbon, are connected by tying threads that form a mesh. The tying threads have a threefold function. They allow for an appropriate mesh geometry, a constant strand cross-section, and the creation of two mats of carbon threads that overlap and are not intertwined.

The preferably nonwoven frame binding net is a weave consisting of warp elements and weft elements, preferably a weave with at least one of the following characteristics:

i. The slits in the tethering network are regular; this geometric regularity will preferably be qualified as follows in a geometric regularity test defined in the description:

The standard deviation in % with respect to the mean of the surfaces of a random panel of 20 slits 5 of the tying network of a 40 x 40 cm grid sample is less than or equal to 4%, preferably to 3%, and even more preferably to 2%;

ii. the warp elements and weft elements of this frame are parallel to the warp threads and weft threads, respectively, of the frame,

iii. The cross-links of this ligament are arranged (in front view) in the slits of the frame.

The weave forms the tying network of the frame; it is a gauze weave; each warp element of this weave comprises two tying threads, and each weft element of this weave comprises one tying thread.

The gauze weave is a weave in which the two warp threads cross around the weft thread, which provides excellent stability at the crossing points.

According to an interesting variant of the invention, the grid can be associated with a corrosion protection system for the metal frameworks of the concrete structure to be consolidated. These means can be metal wires coated with mixed metal oxides (MMO), intended to form electrodes capable of enabling electrochemical action against the corrosion of the reinforced concrete frameworks of the structure to be consolidated.

These MMO metallic threads could be binding threads.

In the tether net:

• each warp element of the weave comprises two warp tying threads and each weft element of the weave comprises one weft tying thread,

• one of the two binding threads passes through the same side C1 of all the weft threads of the frame,

• the other warp tie thread passes through the same side C2 opposite to C1 of all the weft threads of the frame,

• between two successive weft threads of the frame, the warp tie threads cross before the weft weave thread, pass on both sides of the weft tie thread, and then cross again to grasp the weft thread of the frame.

According to interesting embodiments of the invention, the tying threads have at least one of the following characteristics:

i. The binding threads are based on one or more materials chosen from the group comprising, or better still consisting of, carbon, glass, basalt, metals, plant materials, advantageously selected from the subgroup comprising, or better still consisting of, hemp, synthetic materials, advantageously selected from the subgroup comprising, or better still consisting of, aramid, poly[benz(1,2-D:5,4-D')bisoxazol-2,6-diyl-1,4-phenylene], polyethylene, polypropylene, polyamides, polyimides, polyesters;

glass being preferable;

ii. The number (in tex) of the binding threads forming the warp elements is comprised within the following intervals, preferably in ascending order: [5-100]; [10-60]; [15-50]; [20-40];

iii. The number (in tex) of the binding threads forming the weft elements is preferably within the following ranges, in ascending order: [10-200]; [30-150]; [40-100]; [50-80]; iv. The number (in tex) of the binding threads forming the warp elements is equal to 50/- 20 % of the number (in tex) of the binding threads forming the weft elements.

In the preferred embodiment of the grid according to the invention, the tying threads are made of glass (type E). These tying threads have good tensile strength. They are selected according to the invention so that they do not break when subjected to tension during the laying of the grid. Furthermore, they are rot-proof and non-flammable.

In a preferred embodiment:

• Each warp element is advantageously formed by two binding threads, for example 34 tex each and with commercial reference ECG 75.

• Each weft element is advantageously formed by a binding thread, for example 68 tex and with commercial reference ECG 150.

This configuration of 2 binding threads in the warp direction/1 binding thread in the weft direction with a tex equal to the sum of the tex of the other 2 threads allows to avoid tensions in the rest of the frame and to have regularity in the geometry of the meshes.

The tying threads partially obstruct the meshes of the nonwoven frame. Therefore, it is preferable to keep the tying threads as thin as possible to limit clogging of these meshes and thus allow the matrix to pass through the grid. This optimizes the anchoring of the matrix to the grid and the mechanical characteristics of the matrix/grid system, specifically with regard to shear strength.

The manufacture of this grid is advantageously manufactured using conventional means known per se.

MATRIX

The hardenable matrix can be mineral and/or organic.

A hardenable matrix preferably comprises one or more mineral and/or organic binders.

In a preferred embodiment, the hardenable matrix comprises (in parts by weight):

or 100 of binder;

or 1-4000, and in ascending order preferably, 5-2000; 10-1000; 20-500 of mineral fillers;

or 0.01-1000, and in ascending order preferably, 0.05-800; 0.1-500; 0.5-200; 1-50 of at least one resin; or 0-500 of additives, and preferably 0.01-50.

Binder

This binder is preferably mineral, and, even more preferably, is chosen individually or in combination from the group comprising, ideally consisting of:

(i) Portland cements, slag cements, geopolymer cements, natural pozzolans, fly ash, slag, supersulfated cements, calcium sulfates (gypsum, hemihydrate and/or anhydrite), limes (quick, slaked and/or hydraulic), potassium, sodium and/or lithium silicates, and mixtures thereof;

(ii) calcium aluminate (CAC) and/or calcium sulfoaluminate (CSA) based cements and their mixtures; (iii) and their mixtures

In a preferred embodiment of the matrix according to the invention, the binder is, at least in part, constituted by cement.

According to one variant, the binder is at least partly organic, chosen from the group comprising, ideally consisting of: epoxy (co)polymers, (co)polyurethanes, and mixtures thereof.

Mineral fillers

Advantageously, the D50 of these mineral fillers is less than or equal to 1000 pm; and, more advantageously, less than or equal to 800 or even 700 pm.

These mineral fillers are preferably chosen from the group that includes, ideally,:

(i) the subgroup comprising or, better still, consisting of: fillers and/or sands, preferably from silica, calcareous, siliceous-calcareous, magnesian sands and mixtures thereof, siliceous, calcareous and siliceous-calcareous, magnesian fillers and mixtures thereof, and/or from metal oxides, aluminas, and/or from glass beads and natural and synthetic silicate minerals, preferably chosen from clays, micas, metakaolins, silica fumes and mixtures thereof;

(ii) the subgroup of selected lightweight fillers comprising or, better still, consisting of: expanded perlite, expanded vermiculite, silica aerogels, expanded polystyrene, cenospheres (phyllites), hollow alumina beads, expanded clays, pumice, hollow glass beads (3M® type) or expanded glass granules (Poraver®, Liaver®), silicate foam grains, rhyolite (Noblite®);

(iii) and their mixtures.

Resins

These resins are chosen from the group that ideally comprises:

(i)Unsaturated copolymer resins;

(ii) Redispersible powder resins of the subgroup comprising or, better still, consisting of the families of acrylic homo- or copolymer resins, vinyl acetate-ethylene copolymers, styrene-acrylic copolymers, vinyl acetate terpolymers, vinyl versatate and maleic acid dialkyl ester, vinyl acetate and vinyl versatate copolymers, styrene and butadiene copolymers, and mixtures thereof;

(iii) and their mixtures

These resins are intended to increase adhesion and elasticity.

As preferred examples, mention may be made of vinyl acetate-ethylene copolymers.

Additives

Advantageously, the matrix according to the invention comprises at least one of the following additives: a setting retarder, a setting accelerator, a water retainer, a water repellent, a colorant, fibers, an antifoam, a rheology agent, an air entraining agent or foaming agent, a gas generating agent, a retarder.

Preferably, this hardenable matrix has at least one of the following additive characteristics:

- the setting retarder is preferably chosen from the group comprising or even better consisting of calcium chelating agents, carboxylic acids and their salts, polysaccharides and their derivatives, phosphonates, lignosulfonates, phosphates, borates and salts of lead, zinc, copper, arsenic and antimony, and more particularly from tartaric acid and its salts, preferably its sodium or potassium salts, citric acid and its salts, preferably its sodium salt (trisodium citrate), sodium gluconates; sodium phosphonates; sulfates and their sodium or potassium salts, and mixtures thereof;

- the setting accelerator is chosen from the group comprising or even better consisting of alkaline and alkaline earth salts of hydroxides, halides, nitrates, nitrites, carbonates, thiocyanates, sulfates, thiosulfates, perchlorates, silica, aluminum, and/or carboxylic and hydrocarboxylic acids and their salts, alkanolamines, insoluble silicate compounds such as silica fume, fly ash or natural pozzolans, quaternary ammonium silicates, finely divided mineral compounds such as silica gels or finely divided calcium and/or magnesium carbonates, and mixtures thereof; this additional setting accelerator (e) is preferably chosen from the group comprising or even better consisting of chlorides and their sodium or calcium salts; carbonates and their sodium or lithium salts, sulfates and their sodium or potassium salts, calcium hydroxides and formates and their mixtures;

- the water retainer is chosen from the group comprising or even better consisting of polysaccharides and preferably cellulose or starch ethers and mixtures thereof, and preferably from the group comprising methylcelluloses, hydroxyethylcelluloses, methylhydroxypropylcelluloses, methylhydroxyethylcelluloses and mixtures thereof, or from modified or unmodified guar ethers and mixtures thereof or the mixture of these different families;

- the water repellent (i) is chosen from the group comprising, or better still consisting of, fluorinated, silanized, silicone-containing, siloxanated agents, metal salts of fatty acids and mixtures thereof, preferably sodium, potassium and/or magnesium salts of oleic and/or stearic acids and mixtures thereof; - the colorant (j) is chosen from the group comprising, or better still consisting of, organic and/or mineral pigments, and more particularly oxides of iron, titanium, chromium, tin, nickel, cobalt, zinc, antimony and/or polysulfurized sodium aluminosilicates, carbon, cobalt, manganese and zinc sulfides, and/or pigments with high transparency or high infrared reflectance and mixtures thereof;

- The fibers comprise mineral, animal, vegetable and synthetic fibers, more particularly chosen from the group comprising or even better consisting of polyamide, polyacrylonitrile, polyacrylate, cellulose, polypropylene, polyvinyl alcohol, glass, metal, linen, polycarbonate, sisal, jute, hemp fibers and mixtures of these fibers; - The antifoam is chosen from the group comprising or even better consisting of polyether polyols, hydrocarbon molecules, silicone molecules, hydrophobic esters, non-ionic surfactants, polyoxiranes, and mixtures thereof;

- The rheological agent is chosen from the group comprising or even better consisting of thickening agents, fluidifying agents (inorganic and/or organic) and mixtures thereof, and preferably from the subgroup comprising or even better consisting of polysaccharides and their derivatives, polyvinyl alcohols, mineral thickeners, linear polyacrylamides, polynaphthalene sulfonates, polymelamine sulfonates, polycarboxylates and mixtures thereof;

- Air entraining agents or foaming agents are chosen from:

i. sources of anionic surfactants such as alkyl sulfates, alkyl ether sulfates, alkaryl sulfonates, alkylsuccinates, alkylsulfosuccinates, alkoyl sarcosinates, alkyl phosphates, alkyl ether phosphates, alkyl ether carboxylates, and alpha olefin sulfonates, preferably sodium lauryl sulfate, ii. nonionic surfactants such as ethoxylated fatty alcohols, mono or di alkyl alkanolamides, alkyl polyglucosides,

iii. Amphoteric surfactants of the alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulfobetaines, alkyl glycinates, alkyl amphopropionates, alkyl amidopropyl hydroxysultaines type. - The in situ gas generators are chosen from among the products that generate gas in contact with the matrix of the system according to the invention, oxygen, hydrogen, nitrogen, carbon monoxide or dioxide, ammonia, methane. They may be chosen from the adjuvants described in US 7,288,147 and in particular from the families of azodicarbonamide, sodium bicarbonate, organic or inorganic peroxides, toluenesulfonyl hydrazide, benzenesulfonyl hydrazide, toluenesulfonyl acetone hydrazone, toluenesulfonyl semicarbazide, phenyltetrazole, sodium borohydride, dinitrosopentamethylenetetramine;

- The flame retardants are preferably chosen from the group comprising or, better still, consisting of flame retardants having chemical and/or physical actions, halogenated flame retardants, phosphorus flame retardants, nitrogen flame retardants, intumescent systems, mineral flame retardants, metal hydroxides, zinc compounds, borates, antimony oxides, nanocomposites based on clays based on aluminium silicates and mixtures thereof;

preferably from the subgroup comprising or even better consisting of tetrachlorobisphenol A (TBBPA), chloroparaffins, organic phosphates, red phosphorus, phosphonates, phosphinates, melamine, their salts and homologues, aluminium or magnesium hydroxides, zinc hydroxystannates, zinc borate, and mixtures thereof.

These additives have the role of offering a regularity of the material properties and making it possible to meet the precise specifications specific to each application of the dry composition (e.g. cement): mortar, coating, adhesive.

Set retarders and additional set accelerators are products that modify the solubilities, dissolution and hydration rates of the various components of the dry cement composition.

The water retainer has the property of retaining the mixing water before setting. This retains the water in the paste, mortar, or concrete, providing excellent adhesion and hydration. To a certain extent, less water is absorbed into the substrate, its release on the surface is limited, and therefore, there is little evaporation.

Water repellents are intended to reduce water penetration into the dry composition or hardened product. Examples include sodium oleate or magnesium stearate.

The purpose of the colorant is to give the hardened product the desired shade. Examples include iron oxide (Fe2O3) or titanium dioxide (TiO2).

The purpose of fibers is to improve the mechanical strength of the hardened product. Polyacrylonitrile fibers are examples.

Antifoaming agents are used to increase mortar cohesion by limiting the presence of air bubbles. They help reduce the secondary effects of other additives or the addition of air during mixing. Polyether polyols are examples of antifoaming agents.

Rheological agents are intended to modify the consistency of the wet product to adapt it to its application. Examples include sepiolite, xanthan gum, and silica fume.

Foaming agents are intended to provide additional porosity by entraining air during mixing of the mineral binder.

In situ gas generating agents are intended to provide additional porosity by generating air in situ during the mixing of the mineral binder.

Flame retardants protect the hardened product from fire.

HARDENED COMPOSITE STRUCTURE

The invention also has as its subject the hardened composite structure obtained from the system according to the invention as defined in the description, examples and figures.

This toughened composite structure has a service temperature, which corresponds to the average temperature of a structural element, resulting from winter or summer climatic temperatures and the operating temperatures defined by standard NF EN 1991-1-5 in section 5.2. This temperature can reach, for example, at least 80°C.

The invention also relates to a composite structure having an elastic tensile modulus MTE of less than or equal to, in MPa and preferably in increasing order, 100,000, 80,000, 70,000, as well as to the use of such a structure for increasing the resistance to seismic loads of a reinforced concrete or masonry structure, said structure being obtained from a composite system for consolidating structures, comprising a hardenable or hardened matrix and a textile reinforcing grid, wherein the grid comprises at least one layer formed by a framework consisting of flat warp threads and weft threads and has dimensional stability under tension of the meshes of the framework, before the grid is applied to the structure to be consolidated.

PROCEDURE FOR CONSOLIDATION OF WORKS IN REINFORCED CONCRETE OR MASONRY

According to another of its aspects, the invention relates to the implementation of the system comprising the grid according to the invention and the cementitious matrix, to consolidate a structure, specifically of reinforced concrete or masonry, such as the wall of a building, a tunnel, a pipeline, a bridge pillar, etc.

A method for consolidating reinforced concrete or masonry works is thus envisaged, characterised in that it essentially consists of gluing the grid as defined in this description, examples and figures, on the work site with the matrix as defined in this description, examples and figures, possibly after having mixed said matrix with a liquid, preferably water, to obtain a hardenable wet matrix.

More precisely, the hardenable wet matrix is advantageously sprayed onto the work, preferably by means of a pump, then the grid is placed on the unhardened matrix and glued, preferably with a trowel and, if necessary, the matrix is sprayed again at least once, preferably by smoothing the surface of the matrix thus sprayed with the trowel.

Depending on the implementation, the spraying, placement of a new grid, and gluing operations are repeated n times, with n ranging from 1 to 3; these operations can be performed on the surface of the previously sprayed matrix that has not been hardened or has at least been partially hardened.

In practice, the dry formulation of the cementitious matrix is first mixed with a liquid, preferably water.

Mixing rates range, for example, from 10 to 30%.

The grid according to the invention is implemented, ensuring that the warp direction of the grid is arranged on the axis of the tension it wishes to diffuse.

A layer of mortar is applied to the area of the structure to be reinforced, either manually or mechanically. The grating is placed and glued to the mortar layer, for example, using a trowel. The composite system is then completed by applying a final layer (mechanically or manually).

This operation can preferably be repeated up to three times per superposition.

WET FORMULATION AND ITS PREPARATION PROCEDURE

According to another of its aspects, but which is not claimed, the invention relates to a wet formulation for the construction industry comprising the matrix according to the invention, mixed with a liquid, preferably water.

According to another of its aspects, but which is not claimed, the invention relates to a process for preparing the wet formulation according to the invention, which essentially consists of mixing a liquid, preferably water, with all or part of the components of the matrix according to the invention, the rest of the components being gradually incorporated into the mixture if this has not been done before.

USE OF THE GRID ACCORDING TO THE INVENTION

According to another of its aspects, the invention relates to the use of a grid according to the invention to consolidate a work, specifically of reinforced concrete or masonry, by gluing using a wet formulation according to the invention.

WORKS IN THE CONSTRUCTION OR CIVIL ENGINEERING INDUSTRY

The invention also relates to works in the construction industry or civil engineering consolidated using the system according to the invention, after mixing with a liquid (preferably water) the matrix in the form of a dry composition according to the invention, to obtain a wet formulation according to the invention, used to apply, at least once per gluing, the grid according to the invention.

Other details and advantageous characteristics of the invention will become clear below from the description of an example of a preferred, non-limiting embodiment of the invention, with reference to the attached figures in which:

- Figure 1 is a perspective photograph of a preferred embodiment of the grid according to the invention - Figure 2 is a schematic detailed view of Figure 1.

Figure 3 is a sectional view along section line III-III in Figure 2.

- Figure 4 is a view of the sample of grid according to the invention intended to be subjected to the TS test for dimensional stability under tension.

- Figure 5 is a detailed photograph of a manufacturing stage of the grid according to the invention on the loom used for this purpose.

- Figure 6 is a photograph of another manufacturing stage of the grating according to the invention, namely the coating. - Figure 7 is a frontal photograph of the grating according to the invention.

- Figure 8 shows, on its left side, a perspective view of the specimen used in a quasi-static uniaxial tensile behaviour test of the composite system according to the invention, on its right side, a perspective view of the specimen provided at each of its 2 ends with a connection to the testing machine, and in its central part with a detail of this connection.

- Figure 9 is a curve of mean tensile stress (MPa) as a function of strain (mm/mm) in a quasi-static uniaxial tensile behavior test of the composite system according to the invention. - Figure 10 shows a perspective view at the top and a side view at the bottom of the specimen used in a temperature stability test of the composite system according to the invention. - Figure 11 is a curve showing the evolution of stiffness for specimens of the type shown in Figure 8 and allowing an exploratory fatigue study of the composite reinforcement system comprising a grid/matrix according to the invention.

- Figure 12 shows a SATEC type adherometer used in an evaluation of the surface cohesion of the composite system according to the invention, on a concrete support.

- Figure 13 shows a diagram of a bending frame used in bending moment measurement tests on bending beams reinforced with the composite system according to the invention.

- Figure 14 shows the load curves (daN) as a function of the deflection (mm) measured for beams reinforced or not with the composite system according to the invention and subjected to the bending moment test.

- Figure 15 shows the load (N) curves as a function of the deflection (mm) obtained in a test measuring the behaviour of reinforced concrete beams, reinforced or not, against shear stress, using a composite system according to the invention.

- Figure 16 shows the identification of the mechanical characterization parameters of the toughened composite structure, in particular the elastic tensile modulus MTE.

The composite system for consolidating works, specifically reinforced concrete or masonry, according to the invention comprises a hardenable or hardened matrix and a textile reinforcement grid.

-I- GRID

Structure:

The grid is referenced 1 in the figures. It can be compared to a lattice composed of a nonwoven frame 2 and a net 3 securing this frame 2.

The latter is made up of flat 2°c carbon warp threads that are intertwined with flat 2°t carbon weft threads.

The 3-knit weave is a weave that includes 3°c warp elements and 3°t weft elements.

The warp threads 2°c and the weft threads 2°t of the nonwoven frame 2 overlap and are perpendicular. The web formed by the warp threads 2°c may be described as lower because it is intended to be applied to the work to be consolidated, while the upper web is formed by weft threads 2°t, which by convention in the present disclosure have a Face F1 and a Face F2 shown in Figure 3.

In this example, the warp threads 2°c are simply placed on top of the weft threads 2°t. They are not rigidly connected to each other in their contact areas. The cohesion and geometric regularity of the frame 2 are preferably ensured solely by the tying net 3. According to variants of the invention, tying could be provided between the warp threads 2°c and the weft threads 2°t, in all or part of their contact areas, for example by gluing and/or welding.

The perpendicular arrangement of the warp threads 2°c and the weft threads 2°t is also preferable, but the angle between the warp and the weft may be different from 90°, for example between 30° and 120°, excluding 90°.

The grid defined by the warp threads 2°c and the weft threads 2°t delimits the slits 4 (cf. fig. 1 and 7) in a significantly rectangular shape in this example, but could be rhomboidal if the warp/weft angle of the frame differs from 90°.

Each warp thread 2°c and weft thread 2°t consists of a flat bundle of N carbon filaments. In this preferred embodiment:

N is approximately equal to 12,000 (800 tex).

The tensile strength (in MPa) of each thread is substantially 4900.

The tensile modulus (in GPa) of each thread is substantially 230.

The elongation (in %) of each thread is substantially 2.1.

The diameter of the filament is substantially 7 pm.

The density of the filament is substantially 1.8.

The warp threads 2°c and weft threads 2°t are preferably identical in this example, but it is not ruled out to implement warp threads 2°c that are different from each other and/or weft threads 2°t that are identical or different from each other.

These carcass yarns may correspond specifically to the carbon yarns marketed by the company TORAY CARBON FIBERS EUROPE under the designation FT300, T300, T300J, T400H, T700S, T700G, T800H, M35J, M40J, M46J, M55J, M60J, M30S, M40, T1000G, M50J, T600S or T800S.

The warp elements 3°c and the weft elements 3°t of the tying net 3 together form a weave in which each warp element 3°c comprises two warp tying threads 3i°c, 3ii°c and each weft element 3°t comprises one weft tying thread 3°t. The weave of the tying net 3 is a gauze weave or leno weave. As is clearly seen from Figures 2 and 3, the two warp tying threads 3i°c run along the warp according to the following recurring pattern M shown in Figure 3:

• one of the warp binding threads 3i°c1 passes over the Face F1 of a weft thread 2°t' of the frame 2 and the other warp binding thread 3ii°c2 passes over the other Face F2 of said weft thread 2°t' of the frame 2, to enclose the latter;

• the two warp binding threads 3i°c1 and 3ii°c2 cross a first time in the slit 4 delimited by a segment of the weft thread 2°t', by an opposite segment of the following weft thread 2°t" in the warp direction C in figures 2 and 3 and by the two facing segments of the two corresponding adjacent weft threads 2°c of the frame 2, said slit 4 being crossed by a weft binding thread 3°t, in such a way that, after having crossed a first time, the two warp binding threads 3i°c1 and 3ii°c2 pass on each side of the weft binding thread 3°t, then they cross again for the second time in said slit 4, so that the warp binding thread 3i°c1 then passes over Face F1 of the following weft thread 2°t" and the warp thread 3ii°c2 passes over Face F2 of the next weft thread 2°t".

The warp elements 3°c cross the weft threads 3°t of the tying net 3 in the slits 4 of the frame 2, thus also defining regular slits 5 (cf. fig. 7). The warp elements 3°c are substantially perpendicular to the weft threads 3°t of the tying net 3. The warp elements 3°c of the tying net 3 are substantially parallel to the warp threads 2°c of the frame and the weft elements 3°t of the tying net 3 are substantially parallel to the weft threads 2°t of the frame 2.

The 2°t carbon threads of the frame 2 in the weft direction are immobilized by the tying network 3, which guarantees a geometric regularity of the whole.

According to a conceivable variant, the weft elements 3°t of the tying network 3 could comprise, like the warp elements 3°c, two weft tying threads capable of trapping the warp threads 2°c of the frame 2. This further reinforces the cohesion, the resistance to deformation under tension and the regularity of the frame 2. Each warp thread 3i°c, 3ii°c and weft thread 3°t preferably consists of a glass thread. In this preferred embodiment, the number (in tex) of this warp glass tying thread is 35 +/- 5, the number (in tex) of the weft glass tying threads is 75 +/- 5. This warp number of 38 tex represents 51% of the weft number of 75 tex.

These glass tying threads may correspond to the products marketed by the company FULLTECH FIBER GLASS CORPORATION with the name ECG 751/00.7Z 172 SIZING (A-GRADE) and/or ECG 1501/00.7Z 172 SIZING (A-GRADE).

The grid according to the invention can be applied interchangeably with the weft or warp threads on the axis of the tension to be distributed (diffused) (the carbon threads of the weft and warp have an almost equivalent performance in terms of stress recovery)

Because of this, reinforcement can be applied to "absorb" bending stresses and so-called "shear" stresses.

Manufacturing: lattice/coating-impregnation

The grid 1 composed of the non-woven frame 2 made of 2°c,2°t yarns (e.g. carbon) reinforced by a tying net 3, is manufactured as follows, for example using a loom, making the frame 2 and weaving on this frame 2, the 3i°c1, 3ii°c2 and 3°t yarns (e.g. glass) in a gauze frame of the tying net 3.

Figure 5 shows a detail of the loom and in particular of the warp tie threads 3i°c1, 3ii°c2, just after they cross, before being wound around a tie weft thread 3°t (not yet inserted into the loom and not shown in Figure 5), to then cross again and to be wrapped around a weft thread 2°t of the frame 2 (not yet inserted into the loom and not shown in Figure 5).

The use of both warp tie threads and one weft tie thread allows the weft carbon threads to be rigidly joined "geometrically" to the warp carbon threads.

Furthermore, this type of weaving induces a regular tension in the mesh (in the warp and weft directions), allowing the threads to be distributed evenly in all directions. The geometry of each slit 4 of frame 2 or slit 5 of weaving net 3 is highly regular.

The grid, according to this embodiment, is coated by impregnation, for example, with a pure acrylic resin whose glass transition temperature is 25 °C, the minimum film formation temperature is 14 °C and whose dry extract is 46%.

This coating/impregnation ensures and reinforces the dimensional stability of the assembly and the homogeneous distribution of stresses. This ensures effective cooperation between the filaments that make up the 2°C carbon filaments of the frame 2 warp. The coating/impregnation acts as a "fixative," allowing the grid to effectively resist deformation. This allows stresses to be distributed evenly across the surface of the grid and within each carbon thread, facilitating their dissipation.

The grid is preferably, as this example illustrates, manufactured continuously, which allows for effective management of the tensions associated with manufacturing (loom).

The threads are tensioned evenly and consistently, then coated by soaking.

Figure 6 shows the uncoated grid 1b during its circulation on the rollers 11, 12 of the coating machine, one of these rollers 11 being associated with a scraper, one of whose edges, parallel to the axis of the roller 11, is in contact with the grid 1, to form a receptacle containing a coating bath 13 that impregnates the moving grid 1 and then passes between the coating roller 11 and the counter roller 12, to remove the excess coating liquid. The coated grid 1 is dried

After drying, the grid is collected and conditioned on rollers.

The mesh according to the invention can be applied interchangeably with the weft or warp threads along the axis of the tension to be distributed (diffused). The carbon threads of the weft and warp have almost equivalent performance in terms of stress recovery. For this reason, the reinforcement can be applied to "absorb" bending stresses and so-called "shear" stresses.

-II- TR AND TS TESTS

-II.1- TS test for dimensional stability under tension

11.1.1 Method

This test TS consists of cutting a square grid sample E of 40 * 40 cm on a grid roller 1. This sample E is shown in Figure 4.

As can be seen in Figure 4, the sample E is hung on a graduated board 15 by means of two hooks 16 on a horizontal bar 17, so that one of the hooks 16 is fixed at a distance of 2.5 cm (at the distance to the center of the fixing pin adhered to the top of the grid) from one of the upper corners of the sample E and the other hook at a distance of 2.5 cm from the opposite upper corner (from the axis of the fixing hole to the outer edge of the grid). Each hook 16 consists of a threaded rod of 6 mm diameter, bent to form a hook.

The bar is manufactured from an inverted "U"-shaped metal profile with a perforation at its base. Hook 16 is rigidly attached to the U-shaped bar, as it is pass-through and secured by a nut/locknut system. The top edge of sample E is aligned with the horizontal axis corresponding to the zero scale of scale table 15.

The middle slit 4 is located within the lower terminal line of the slits 4 of sample E.

This middle slit 4 is the one closest to the center of this lower terminal line of sample E.

The position of the lower edge of sample E, located just below the middle slit 4, is indicated on the graduated table 15. The value V0 is read in cm, corresponding to the length between the zero scale of the graduated table 15 and the position of the lower edge indicated on the graduated table 15.

A weight 20 of 1 kg or 2 kg is then fixed in the center of the sample E by means of a hook 18 including a curved end portion 19 which is inserted into the middle slit 4.

Hook 18 consists of a metal wire bent at both ends to form a double hook for stowing sample E by weight.

Immediately after weight 20 has been placed, the position of the lower edge of sample E, located just below the middle slit 4 or 5, is indicated on the graduated table 15. The value V1 is read in cm, corresponding to the length between the zero scale of the graduated table 15 and the position of the lower edge indicated on the graduated table 15.

Its deformation is calculated in cm D1 = V1 - V0 if the weight 20 is 1 kg

Its deformation is calculated in cm D2 = V2 - V0 if the weight 20 is 2 kg.

11.1.2 Results

V0 = 40 mm

V1 = 40 mm D1 = 0

V2 = 40 mm D2 = 0

-II.2- TR test of geometric regularity

11.2.1 Method

This test TR consists of cutting a square grid sample E measuring 40 x 40 cm from a grid roll 1 as it is obtained at the end of production and has therefore not been unrolled or handled. This sample E is shown in Figure 4.

The surface area of a random panel of 20 slits in this sample is calculated. In the case of a rectangular slit, as is the case in this preferred embodiment, the length and width of each slit are measured, followed by the product of these two dimensions to obtain the surface area. In the case of a geometric shape other than rectangular, the appropriate dimension measurements and calculations are performed.

The standard deviation of the frame slit area is calculated for a random panel of 20 slits. The slits can be slits or meshes 4 of frame 2 or slits or meshes 5 of tying net 3.

11.2.2 Results

II.2.2.1 Carbon frame 2

Table 1

continued

Sides 1 and 2 are contiguous.

The mesh area is calculated as follows: side 1 * side 2

11.2.2.1 Glass tether net 3

Table 2

continued

-III- CEMENTARY MATRIX

1- Raw materials

1.1 Hydraulic binder:

1.1.1. Portland cement type CEM I 52.5N - SR5 CE PM - CP2, with a density of 3.17 g/cm3 and a Blaine specific surface area of 3590 cm2/g.

1.1.2. Calcium oxide with a minimum apparent density of 93% and a particle size range of 0-100 |jm.

1.2 resin:

Redispersible powder resin based on acrylate copolymer with a density of 450-650 g/l, pH 7-8, glass transition temperature 10 °C and minimum film formation temperature 0 °C (after redispersion in water).

1.3 mineral fillers:

1.3.1 Calcareous filler: pure crystalline natural calcium carbonate (CaCO3 s 99%) with Mohs hardness 3, with an oil absorption of 20 ml/100 g (ISO 787-5) and a mean diameter of 8 jm.

1.3.2 Siliceous fillers:

1.3.2.1 silica sand with a granulometry of 75-300 jm.

1.3.2.2 silica sand with a granulometry of 200-800 jm.

1.4 Additives:

1.4.1 Thickener: amorphous silicic acid with a density of 200 kg/m3 and a specific surface area of 18-22 m2/g.

1.4.2 Water retainer: methylhydroxyethylcellulose with a rotoviscose viscosity of 20,000-27,000 mPa.s (in 2% aqueous solution/20 °C).

2- Operating mode:

* 3 kg of powder comprising the binder, resin, mineral fillers and additives are prepared and mixed for 3 minutes in a Guedu laboratory mixer (model 4.5 NO) with a useful capacity of 3.5 liters at a speed between 545 and 610 revolutions/minute.

* The 3 kg of powder obtained are mixed in a Perrier laboratory mixer for 1 minute at a speed of 140 revolutions/minute, then the walls of the container are scraped and mixing is continued for 2 minutes at a speed of 140 revolutions/minute.

-IV- EVALUATION TESTS OF THE GRID/MATRIX COMPOSITE SYSTEM ACCORDING TO THE INVENTION IV.1 Quasi-static uniaxial tensile behavior: measurement of the elastic tensile modulus MTE Test type:

The identification of the intrinsic properties of the grid/matrix composite system according to the invention, in the absence of a standardized procedure, is based on a direct tensile test very suitable for cracking materials and validated on the basis of a theoretical-experimental approach [1]: "R. CONTAMINE, A. SI LARBI, P. HAMELIN "Contribution to direct tensile testing of textile reinforced concrete (<t>R<c>) composites". Materials Science and Engineering: A; 528 (2011), pp. 8589-8598".

Dimensions of the test body:

Figure 8 shows the test specimens 100, which are composed of a grid/matrix composite system plate 101 (100 x 500 mm2) and bonded aluminum beads 102 (4 x 100 x 100 mm) (double sandblasted and bonded with epoxy adhesive at the plate ends). These beads 102 are each connected to the tensile testing machine via a joint 103. The carbon/glass grid system implemented according to the invention includes a single grid bonded by means of the cementitious matrix. The thickness of the hardened composite system is 3 mm.

Tools:

The test was performed on a 5-ton ZWICK universal tensile tester. It was a monotonous static test with a load increase rate of 1 mm/min (until the specimen failed).

The instruments used include two ±20 mm LVDT displacement sensors placed centrally (laterally and vertically) on both sides of the specimen. A force sensor, positioned in a suitable position, allows the evolution of the applied stress to be obtained.

Results/Conclusions:

Six identical specimens are manufactured and analyzed.

The analysis of the results consists of drawing the stress-strain curve (figure 9).

It is a question of considering an average tension (a plausible hypothesis given the cracking obtained) in the textile/mortar composite material:

a and b: the height

The mean strain is given by the ratio of the measured displacement ALc to the measured length lc

Alc: elongation lc: distance between sensors (200 mm).

The qualitative similarities evident in the average stress-strain curves are quite clear, as they all exhibit behavior characterized by four distinct phases. Figure 16 identifies the overall mechanical properties of the textile-mortar composite materials studied. The E1 value of the elastic tensile modulus (MTE) characterizes the composite structure according to the invention, specifically with regard to the seismic load resistance that the structure is capable of providing to the structures it consolidates.

The results obtained are as follows:

Thus, it appears that the reproducibility of the results in the six samples, both qualitatively and quantitatively, is established. Furthermore, the patterns of behavior obtained reflect the good performance of the grid/matrix composite system according to the invention. Indeed, whether it concerns the first zone (stiffness and initial cracking stress) or the stress at rupture (on the order of 30 MPa), the properties obtained are quite interesting. Finally, the relatively high levels of initial stiffness (on the order of 50,000 MPa) and initial cracking stress suggest a very good initial interaction between the constituent elements of the grid/matrix composite system according to the invention.

IV.2 Thermal stability of the grid/matrix composite system according to the invention

Type of essay:

In the absence of a test procedure specifically adapted to textile-mortar, the temperature behavior of the grid/matrix composite system according to the invention is evaluated using a double-skin tensile/shear test (parallel concrete blocks assembled on two symmetrical faces using reinforcing materials). This test, initially designed for polymer-based composite materials, specifically carbon-epoxy, is recommended by the working group of the French Association of Civil Engineering (AFGC). The dimensions of the specimens and the rigid connection surface are defined to minimize the effects of local stresses and allow operation under average stress.

Dimensions of the test body:

Figure 10 shows concrete blocks 110 with dimensions of 140 mm x 140 mm x 250 mm (concrete prepared and implemented according to standard NF EN 18-422). The carbon/glass grid system implemented according to the invention includes a single grid glued by means of the cementitious matrix. The thickness of the composite system, once hardened, is 3 mm. The reinforcement system takes the form of two bands 111, each with an anchorage length of 200 mm and a width of 50 mm. The bands 111 are arranged on two opposite faces of the two blocks 110 and connect them together, keeping their two end faces facing each other, a separation A1.

Tools:

The separation (displacement) of the two blocks (Al) is continuously recorded by displacement sensors 112 (figure 10) of LVDT type with a stroke of ± 5 mm, precision 10-4 mm and the change speed is 1 mm/min.

Results/Conclusions:

- Tensile/shear test at 2 MPa for 30 min at 20°C, 60°C and 80°C

The results obtained demonstrate the absence of creep of the composite material throughout the entire test period (30 minutes), regardless of the temperature tested (20°C, 60°C, 80°C). This demonstrates the good resistance of the grid/matrix composite reinforcement system according to the invention under thermal stimulation.

- Tensile/shear test at 2 MPa for 12 hours at 80 °C

The results obtained validate the stability of the composite grid/matrix reinforcement system according to the invention, for an operating temperature of 80°C and a shear rate of 2 MPa. Indeed, after stabilization due to loading, creep of the assembly is practically nonexistent within a period of 12 hours.

IV.3 Exploratory fatigue study of the composite rebar/matrix reinforcement system according to the invention

Type of essay:

The lack of a standardized procedure for characterizing textile-mortar composite materials led the inventors to design a method tailored to cracking materials. This is a monotonic static fatigue test. The objective is to evaluate, based on direct tensile tests, the configuration's ability to withstand 1000 loading cycles. To better reflect the stresses to which the composite grid/matrix reinforcement system according to the invention could be subjected during repair, ripple fatigue was chosen. Over a cycle, therefore, a variation ranging from 0 to 60% of the maximum tensile stress (i.e., from 0 to 18 MPa) is applied.

Dimensions of the test body:

The sample bodies used are the same as the sample bodies 100 described above and shown in Figure 10. The carbon/glass grid system implemented according to the invention includes a single grid bonded by means of the cementitious matrix. The thickness of the composite system, once hardened, is 3 mm.

Tools:

The test was performed on a ZWICK universal tensile machine with a capacity of 5 tons and a load increase rate of 1 mm/min (until the specimen failed). The instruments used included two ±20 mm LVDT displacement sensors positioned centrally (laterally and vertically) on both sides of the specimen. A force sensor positioned appropriately allows the evolution of the applied stress to be measured.

Results/Conclusions:

The analysis of the results consists mainly of evaluating the macroscopic damage of the specimen, taking as a reference the change in stiffness (increasing Young's modulus E+, decreasing Young's modulus E-, dissipated energy J, deformation per cycle, accumulated residual deformation, deformation at maximum stress)(Figure 11).

The nearly constant stiffness evolution (E+ or E-) highlights the virtual absence of macroscopic degradation of the composite grid/matrix reinforcement system according to the invention over 1000 cycles. This clearly indicates the suitability of the composite grid/matrix reinforcement system according to the invention to withstand static fatigue loading at 1000 cycles and suggests satisfactory performance for a significantly higher number of cycles.

The energy dissipated per cycle is significantly greater in the first measurement cycle, where it largely corresponds to crack formation. Beyond that, its evolution is almost constant over the following 999 cycles. The same mechanisms are mobilized (in stable proportions) from the second cycle onward, suggesting that the potential creation of additional cracks from the second cycle onward is nonexistent or marginal. This latter suggestion seems all the more realistic when supported by the evolution of the residual strain, which remains practically stable beyond the first cycle.

Thus, the composite grid/matrix reinforcement system according to the invention is ideal for beam repairs involving bending stresses (bending moment).

IV.4 Evaluation of the surface cohesion of the composite grid/matrix reinforcement system according to the invention, on a concrete support

Type of essay:

In order to verify the performance of the composite grid/matrix reinforcement system according to the invention, with respect to peel-off stresses, surface cohesion tests were carried out following the procedure described in standard EN ISO 4624 Paint and varnish - Tensile tests, referenced in general standard NF P98-284-1 [September 1992 Tests on flooring - Waterproofing products for engineering works - Resistance to induced cracking - Part 1: tests on cast products adhered to the support. The adhesion of the composite material to a concrete-type substrate is measured by a direct tensile test].

Dimensions of the test body:

The concrete used to make the slabs is defined by a 28-day compressive strength of at least 30 MPa. The carbon/glass grid system implemented according to the invention comprises a single grid bonded by means of the cementitious matrix. It is applied as a single layer on the surface of the latter. The thickness of the composite system, once hardened, is 3.0 mm ± 0.2 mm. Then, after the test, six metal pellets are bonded using an epoxy mortar with a tensile strength greater than 10 MPa.

Tools:

The adherometer used is of the SATEC type (figure 12 in which (120): outer ring - (121): metal pads - (122): composite system - (123): concrete support). It allows a tensile stress to be applied manually at a constant speed until it breaks within a period of 90 s.

Results/Conclusions:

The average bond strength, defined as the ratio of the average breaking load to the nominal surface area of the tablet, is calculated as follows. The latter, equal to 2.1 MPa, is greater than 2 MPa. Furthermore, the observed failure is cohesive, breaking in the concrete substrate. The combination of these two results confirms that the composite grid/matrix system according to the invention is suitable for reinforcing concrete or masonry structures.

IV.5 Experimental results on beams under bending (bending moment) reinforced with LANKOSTRUCTURE TRM composite material

Type of essay:

The objective is to quantify the performance of the inventive grid/matrix composite system in the case of a reinforced concrete beam repair with respect to flexural loads (bending moment). For this evaluation, design is carried out according to a regulatory approach and in accordance with the experimental means available in the laboratory. This design is performed at the ULS (Ultimate Limit State) and the prerequisites are as follows:

- Protection against shear stress fracture

- Fracture of the reinforced concrete beam at pivot A (reinforcement assessment)

- Avoid shear stress interaction (4-point bending)

This maintains a maximum ultimate load of 12 tons. Furthermore, the beam is deliberately damaged before the implementation of the grid/matrix composite system according to the invention, and the plastification of the tensioned frames (residual strain rate of approximately 350 pm/m) constitutes the damage criterion considered.

Dimensions of the test body:

Figure 13 of a V-beam reinforced by a carbon/glass grid system according to the invention, which includes a single grid glued together using the cementitious matrix and which is presented in the form of a band 200 with a width corresponding to the width of the beam being 150 mm and a length equal to 195 cm, which is 5 cm less than the effective length of the beam analysed, so that there is no parasitic contact between the reinforcing element and the support. The thickness of the composite system, once hardened, is 3.0 mm ± 0.15 mm.

Tools:

The tests are carried out in a suitable flexural frame. This is a 4-point flexure (f1 f2 f3 f4) (see Fig. 13). This is done to avoid shear stress in the central section. The load is applied progressively (statically) in a monotonous manner until failure. Direction is achieved by force (regular load increase). The instruments used include:

- a force sensor with a capacity of 200 kN;

- 201 strain gauges (120 ohms) arranged over the height of beam P.

- a displacement sensor 202 (LVDT ± 25 mm) arranged in the center of the beam

Additionally, the comparative evolution of crack opening in the central part of the beam is established using an image correlation system.

Results/Conclusions:

The load-deflection curves associated with the two beams from the same batch (the sound reference beam and the damaged reinforced concrete P beam repaired using the grid/matrix reinforcement system according to the invention) (Figure 14) illustrate qualitatively similar behaviour, although the initial stiffness of the beam reinforced by the composite grid/matrix system according to the invention is lower due to damage before the repair.

Beyond this reduced area, which reflects the macroscopic integrity of the reference beam, the slope of beam P reinforced by the composite grid/matrix system according to the invention is slightly higher due to the effective formation of crack bridges. A final non-linear area then emerges, reflecting the progressive degradation of the beam (mainly the steel frames) and, where applicable, of the reinforcement indicated. From a quantitative point of view, it is clear that the composite grid/matrix system according to the invention contributes to postponing the "inflection" point (called the "yielding threshold") relative to the reference beam. Thus, an increase of approximately 20% is observed in terms of the load at failure, and an increase of approximately 10% is established in terms of the yielding load of the steel frames.

With regard to unitary crack opening, qualitatively very similar behaviors are also observed. However, the reinforcing effect of the grid/matrix composite system according to the invention is clearly demonstrated. Indeed, unitary crack opening is significantly reduced for an equivalent load level, up to high load levels corresponding to those expected in the Serviceability Limit State (SLS), where problems associated with crack opening are central.

Type of essay:

The objective is to quantify the performance associated with the grid/matrix composite system according to the invention in the case of repair of a reinforced concrete beam subjected to shear stress loads. For this assessment, a sizing is carried out according to a regulatory approach (BAEL and EUROCODE 2) and based on the experimental means available in the laboratory. The prerequisites for this sizing are as follows: - Protection against failure due to bending moment

- Locate the break on one side only to better understand the physical phenomena

- Beam failure due to "pure" shear (oblique macrocrack)

Dimensions of the test body:

The composite grid/matrix reinforcement system according to the invention is implemented in the beam in two configurations: -1 single continuous band of 650 mm around the entire perimeter

- 8 bands of 30 mm width on the side and bottom faces

The effective length of the beams analyzed is 2 m. The thickness of the composite system, once hardened, is 3.0 mm ± 0.25 mm.

Tools:

The instruments consist of:

- 2 strain gauges (120 ohms) arranged on the frames (1 on the transverse steels of the undersized part), the last one is glued to the central part of the longitudinal steels)

-1 displacement sensor (LVDT ± 25 mm) placed in the middle of the beam span

-1 force sensor with 50 kN capacity

Results/Conclusions:

The load-deflection curves obtained confirm the very good dispositions of the composite grid/matrix system according to the invention for repair and/or reinforcement with respect to shear stress (Figure 15).

The composite grid/matrix system according to the invention contributes significantly to increasing the ultimate load relative to the reference beam. Thus, the differences are roughly 15 to 20%, which is all the more satisfactory since only one layer of composite material was used.

Furthermore, the local scale-up demonstrates the ability of the grid/matrix composite reinforcement system according to the invention (regardless of the configuration considered) to generate a level of steel deformation much higher than that of the reference beam. This parameter is an indicator of the structural element's ductility.

Claims (10)

1. Reinforced concrete or masonry consolidation grid comprising at least one layer formed: - on the one hand, by a frame (2) consisting of flat warp threads (2°c) and weft threads (2°t); - and, on the other hand, by a net (3) for securing the frame: where the tying network is such that it guarantees the geometric regularity and dimensional stability under tension of the frame meshes, before the application of the grid on the work to be consolidated, wherein the tying net of the frame is a weave consisting of warp elements (3°c) and weft elements (3°t), characterized in that this weave is a gauze weave; each warp element (3°c) of this weave comprising at least two tying threads (3i°c, 3ii°c), preferably two, and each weft element (3°t) of this weave comprising at least one tying thread (3°t, 3°t'), preferably one, and in that: • each warp element (3°c) of the weave comprises two warp tying threads (3i°c, 3ii°c) and each weft element (3°t) of the weave comprises one weft tying thread (3°t, 3°t'), • one of the two binding threads passes through the same side C1 of all the weft threads of the frame, • the other warp tie thread passes through the same side C2 opposite to C1 of all the weft threads of the frame, • between two successive weft threads of the frame, the warp tie threads (3i°c, 3ii°c) cross before the weft tie thread (3°t, 3°t'), pass on both sides of the weft tie thread and then cross again to grab the weft thread of the frame. 2. Composite system for consolidating works, specifically reinforced concrete or masonry, comprising a hardenable or hardened matrix and a grid according to claim 1. 3. System according to claim 2, characterized in that the dimensional stability under tension is qualified as follows in a TS test: The deformation of a 40 x 40 cm sample suspended by its two upper corners in a vertical plane and subjected to the tensile stress of a mass of 1 (D1 strain) or 2 kg (D2 strain) fixed to the center of the lower edge of the sample, is such that: • D1 less than or equal to, in cm and in ascending order preferably: 2.5; 1.5; 1.0; 0.8; 0.6; 0.5; 0.3; 0.2; 0.1; • D2 less than or equal to, in cm and in ascending order preferably: 5; 4; 3; 2; 1.8; 1.6; 1.5; 1.4; 1.2; 1.0; 4. System according to claim 2 or 3, characterized in that at least a portion of the wires of the grid are coated/impregnated with at least one polymer, preferably chosen from the group comprising, or better still constituted by: • (meth)acrylic (co)polymers, advantageously selected from the subgroup comprising, or better still consisting of, copolymers of alkyl esters advantageously comprising from 1 to 8 carbon atoms, with acrylic acid or methacrylic acid, in particular those chosen from the family comprising, or better still consisting of, preferably methyl acrylate, ethyl acrylate, butyl acrylate, ethyl-2-hexyl acrylate and their corresponding ones with methacrylic acid; and mixtures thereof; • (co)polymers of vinyl esters advantageously selected from the subgroup comprising, or better still consisting of, homopolymers and copolymers of vinyl acetate, in particular those chosen from the family comprising, or better still consisting of, copolymers of vinyl acetate and ethylene, (co)polymers of vinyl chloride such as copolymers of vinyl chloride and ethylene, (co)polymers of vinyl laurate, (co)polymers of vinyl versatate, (co)polymers of vinyl esters of alpha monocarboxylic acids, saturated or not, branched or not, advantageously comprising 9 or 10 carbon atoms, homopolymers of vinyl esters of alkylcarboxylic acids, saturated or not, branched or not, advantageously comprising 3 to 8 carbon atoms, copolymers of these latter homopolymers with ethylene, vinyl chloride and/or other vinyl esters; and mixtures thereof; • (co)polymers of styrene with butadiene or with one or more acrylic esters advantageously selected from the subgroup comprising, or better still consisting of, ethylenically unsaturated alkyl esters advantageously comprising from 1 to 8 carbon atoms of (meth)acrylic acid, preferably methyl acrylate, ethyl acrylate, butyl acrylate, ethyl-2-hexyl acrylate and their corresponding compounds with methacrylic acid; and mixtures thereof; • (co)hot-melt polymers, advantageously selected from the subgroup comprising, or better still consisting of, polyethylenes, polypropylenes, polyesters, polyamides, ethylene-propylene-diene monomer copolymers (EPDM) and mixtures thereof; • and their mixtures. 5. System according to at least one of claims 2 to 4, characterized in that the weft threads and the warp threads of the frame are included in two parallel planes. 6. System according to at least one of claims 2 to 5, characterized in that the hardenable matrix comprises (in parts by weight on a dry basis): or 100 of binder; or 1-4000, and in ascending order preferably, 5-2000; 10-1000; 20-500 of mineral fillers; or 0.01-1000, and in ascending order preferably, 0.05-800; 0.1-500; 0.5-200; 1-50 of at least one resin; or 0-500 of additives, and preferably 0.01-50. 7. Cured composite structure obtained from the system according to at least one of claims 2 to 6. 8. Method for consolidating reinforced concrete or masonry work, characterized in that it consists of gluing the grid as defined in claim 1, on the work with the matrix as defined in claim 2 or 6, after having mixed said matrix with a liquid, preferably water, to obtain a hardenable wet matrix. 9. Method according to claim 8, characterized in that the hardenable wet matrix is sprayed onto the work, preferably by means of a pump, the grid is then placed on the unhardened matrix and glued, preferably with a smoothing machine and, if necessary, the matrix is sprayed again at least once, preferably smoothing the surface of the matrix thus sprayed with the smoothing machine. 10. Use of a grid according to claim 1 or as mentioned in claim 2 for consolidating, in particular, a reinforced concrete or masonry work, by gluing, with a wet formulation comprising the matrix as defined in claim 2 or 6, mixed with a liquid, preferably water.